This invention relates to boring heads and in particular to such heads for boring deep holes.
The term "boring" as used throughout this specification should be interpreted to include not only a simple boring operation in which a hole is bored in a formerly solid workpiece but also a counterboring operation in which an existing hole is increased in diameter. References to "boring head" and "boring tool" should similarly be interpreted to include a head and tool suitable for both simple boring and counterboring.
When boring a deep hole a boring tool is conventionally carried in a boring head which is secured to a long boring bar. This bar may be rotated by such means as an electric or hydraulic motor and advanced within a stationary workpiece as the boring operation progresses. Alternatively the workpiece may be rotated and the boring bar held stationary or both the workpiece and boring bar may be rotated in the same direction at different speeds or in opposite directions. Using one of these procedures holes in excess of thirty feet deep can be bored.
One of the main problems encountered in such a deep boring operation is the accurate locating and guiding of the boring tool.
It is an object of the present invention to provide a deep hole boring head which overcomes the above problem in an efficient and simple manner.